This invention relates generally to the field of vascular access catheters. More specifically, it relates to a catheter introducer assembly having a special mechanism for retracting the introducer needle and shielding the introducer needle after introduction of the catheter into a blood vessel.
Vascular access catheters are commonly used in the medical and surgical arts for gaining access to the vascular system of a patient, for example, to infuse fluids into a patient's blood vessel. Such devices are introduced into the blood vessel by means of a sharp needle. The needle makes an initial opening in the vessel. Once the needle has successfully penetrated the vessel, a catheter is threaded over the needle and into the blood vessel. The needle is then withdrawn from the blood vessel with the catheter remaining in the vessel.
Since such a procedure necessarily involves contact between the needle and the patient's blood, there is a risk that the needle will infect third parties if the patient is infected with a blood borne disease such as AIDS or hepatitis. Since the incidence of AIDS and hepatitis has increased in recent years, there has become an increased awareness of the risks posed by catheter introducer needles. For this reason, several attempts have been made to design catheter introducers which shield catheter introducer needles.
This invention relates to a particular class of catheter introducer, namely introducers of the type sold by Becton Dickinson and Company of Franklin Lakes, N.J. under the trademarks Angioset.RTM. and Intima.TM.. Such catheter introducers are described in U.S. Pat. Nos. 4,177,809 and 5,163,913 which are incorporated herein by reference. The Angioset.RTM. and Intima.TM. devices comprise a catheter, a tube and a needle and stylet disposed in the catheter and tube. Once the catheter has been introduced into the blood vessel, the needle is withdrawn by pulling the stylet. When the needle is fully withdrawn, the needle and stylet can be disposed of. When such a procedure is employed, the needle and stylet may be contaminated with blood. There is therefore a need to provide a catheter introducer of the Angioset.RTM. and Intima.TM. type which avoids the risk of blood contamination by the needle and stylet.